EPE Association: EPE 1995 - 45 - Dialogue Session DS6a: Drives: Simulation and User/Application Experiences

EPE 1995 - 45 - Dialogue Session DS6a: Drives: Simulation and User/Application Experiences
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1995 - Conference > EPE 1995 - 45 - Dialogue Session DS6a: Drives: Simulation and User/Application Experiences

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   ESTIMATION OF INDUCTION MOTOR SPEED IN FUZZY LOGIC SYSTEM
By Z. Krzeminski [View]
[Download]

Abstract: The observer system for the induction motor with simultaneous estimation of the rotor speed is analysed. The multiscalar model dependencies for steady state are used to calculate the rotor speed. Errors in dynamical states of the system are caused by inaccuracy of the calculated speed. A fuzzy logic system is proposed to correct the rotor speed. The proposed system is applied to the non-linearly controlled induction motor fed by voltage source inverter and results of simulations are presented.

   POLE PLACEMENT STRATEGY FOR SLIDING MODE CONTROLLER IN Z-RANGE
By P. Matthes [View]
[Download]

Abstract: The paper deals with the design of a sliding mode speed controller for an inverter fed induction machine. Efficient system pole locations are used. A self developed program supports the menue-assisted controller optimisation.

   DYNAMIC ANALYSIS OF NON-SINUSOIDALLY SUPPLIED INDUCTION MACHINE BASED ON THE FINITE ELEMENT METHOD
By R. De Weerdt; K. Hameyer; R. Belmans [View]
[Download]

Abstract: The analysis of a squirrel-cage induction motor based on the finite element calculation is described. The finite element calculations are used to generate an extended motor model describing the motor as a set of coupled windings. The significant difference with conventional motor models as the d-q-model is that the inductance matrix in the model includes saturation and motor slotting in a natural way. Both are described as a ripple on the inductances. Once the model is calculated, it is used in simulations by solving the set of voltage differential equations describing the coupled windings. Simulations are performed, both with and without motion. Voltage supply can be both sinusoïdal and time dependent when an inverter is used.

   MODELLING AND SIMULATION OF ELECTRICAL DRIVES AT NORMAL AND FAULT CONDITIONS
By R. Szczesny; P.J. Chrzan; K. Iwan [View]
[Download]

Abstract: An approach to modelling and simulation of electrical drives at normal and fault conditions is described. Modern simulation methods and models of converter-machine associations are presented. The application of different software packages in converter systems simulation are discussed and TCAD package is chosen. The principal features of TCAD version for Windows are presented and its usefulness for normal and fault conditions study is proved. For an example of application the induction motor fed by voltage source PWM inverter is chosen. Simulation and experimental results for both normal and fault conditions are given and a good agreement has been reached. In the conclusions some suggestions concerning simulation methodology in research and engineering practice are given.

   FUZZY LOGIC SUPERVISION OF ADAPTIVE GENERALIZED PREDICTIVE CONTROL OF INDUCTION MOTOR
By M. A. Brdys; W. L. Sim [View]
[Download]

Abstract: The recently proposed Adaptive Generalized Predictive Control (GPC) for induction motor in [3] is further investigated. A supervisory controller is proposed which updates on-line GPC control loop weights to improve the transients responses and robustness. The design of the supervisory controller employs a fuzzy logic philosophy. The approach is motivated by the fact that relationship between weights and the transient properties cannot be realized by a suitable mathematical model while sufficient qualitative knowledge exists. Feasibility of such an approach is demonstrated by simulation studies of the overall controller operation.

   MODELLING AND OPERATION OF A NONLINEAR SWITCHED RELUCTANCE MOTOR DRIVE BASED ON FUZZY LOGIC
By C. Elmas; O. F. Bay [View]
[Download]

Abstract: In recent years, switched reluctance motors have occupied a wide spectrum of applications for variable speed drives, because of their simplicity and versatility of control. This paper introduces an attempt to use fuzzy logic to model and control a switched reluctance motor drive. Fuzzy based modelling does not require an accurate mathematical model which is very difficult to obtain from a switched reluctance motor (SRM) because of its inherit nonlinearities. An application of fuzzy sets to the SRM drive control was also applied to the speed loop, replacing the conventional PI controller. The results of applying the fuzzy logic controller (FLC) to SRM were compared to those obtained by the application of a conventional PI system. Compared to a PI control the fuzzy logic control provided a better response in terms of accuracy, and insensitivity to changes in operating conditions. The fuzzy controller shows robustness over a wide range of operations.

   CONTROL OF SELF-COMMUTATED SYNCHRONOUS MOTOR WITH DYNAMIC DECOUPLING
By K. Zawirski [View]
[Download]

Abstract: In the paper a theoretical background of a new control method for self-commutated synchronous motor, which improves drives dynamic properties is proposed. The method bases on analysis of existing cross-couplings in control structure and compensation their influence by introduction of control decoupling blocks generating proper signals. This approach becomes similar to the method used for vector-oriented control in the case of drive with autonomous inverter.

   REDUCED ORDER MODEL OF AN INDUCTION MOTOR DRIVE: SENSITIVITY STUDY FOR AN ADAPTIVE CONTROL
By I. Slama-Belkhodja; B. de Fornel [View]
[Download]

Abstract: The induction motor, supplied by a chopper-filter-inverter system is modelled by a nonlinear seven order system. Two reduced order models are presented: An Input/Output one identified with the Recursive Least Squares algorithm and an analitic one. Their sensivities to parameter variations are discussed in vue to apply an adaptive control.

   A SIMULATION TOOL FOR INDUCTION MOTOR CONTROL
By P. Marino; V. Mungiguerra; M. Porzio; R. Setola; F. Vasca [View]
[Download]

Abstract: A simulation tool for the dynamic analysis of scalar and vector controlled induction motor is proposed. The tool is builded under the MATLAB with SIMULINK programme environment. The ac drive considered consists of choppered power supply, filters, voltage source inverter, induction motor, mechanical load, controller. Each element of the whole system is represented as a Simulink block and it can be independently simulated or connected to the others in order to analyze their interaction. The tool is used to design and to test the effectiveness of an extended Kalman filter as :flux observer and rotor resistance estimator. Two different solutions to ensure good filter performance in the presence of a low switching frequency inverter are proposed: the variable sampling period technique and the voltage averaging approach. Simulation results on an high power ac drive are also provided.

   CONTROL OF INDUCTION MOTOR DRIVES USING DISCRETE PREDICTIVE FRAME
By B. Jacquot; B. Delemontey; B. de Fornel; C. Iung; J. Bavard [View]
[Download]

Abstract: This paper presents a high dynamic control of high-power induction motor fed from PWM inverter. First, the field-oriented control is presented. This method uses continuous motor modelling. Operating at low switching frequency, sampling leads to non-negligible approximations during high transient. So a new discrete model that takes into account PWM is developped. Its utilization allows exceptional torque dynamical, a great accuracy, and a good decoupling between torque and flux.

   ADVANCES IN SWITCHED RELUCTANCE DRIVE SYSTEM DYNAMIC SIMULATION
By C. R. Elliott; J. M. Stephenson; M. C. McClelland [View]
[Download]

Abstract: This paper describes the simulation of complete Switched Reluctance drive systems with a commercially available dynamic simulation package (Simulink™). A well established technique for modelling the non-linear characteristics of the Switched Reluctance Motor (SRM) is used, and the reasons for this justified. Experimental validation of the simulator is provided along with example simulation results. The resulting system is user friendly and allows rapid model building but with simulation time within practical limits.

   PARAMETER ESTIMATION FOR INDUCTION MACHINES
By R. J. A. Gorter; J. L. Duarte; P. P. J. van den Bosch [View]
[Download]

Abstract: An identification procedure for estimation of induction machine parameters based on on-line measured data is proposed. By utilizing the switching harmonics of the inverter all machine parameters, except the stator resistance, can be identified in an operating point. An important step in the identification procedure is the transformation of measured signals to rotor coordinates. This yields the possibility to estimate both single-cage as double-cage rotor models. The method is tested on a double-cage 11 kW induction machine.

   ELECTRIC ENERGY CONSERVATION IN PUMPING PROCESSES AT A REFINERY
By R. M. Stephan; M. Americo; A. G. G. Lima; A. Rodrigues [View]
[Download]

Abstract: This paper describes a joint project carried out by UFRJ, CEPEL and REDUC partially sponsored by PROCEL (Brazilian Program on Electric Energy Conservation). The main objective was to study the application of Adjustable Speed Drives (ASD) systems to control the flow of oil in substitution to throttling valves. Energy saving, payback time and power harmonic aspects are considered.

   SIMULATION OF A PWM CONVERTER USING ICAP/4 TO VERIFY THE DESIGN
By M. Deghadi; J. D. Triplett [View]
[Download]

Abstract: A three phase Pulse-Width Modulated (PWM) converter is ready for building. The circuit will first be simulated using ICAP/4 software to verify the design. This paper will describe the design and show the simulation results for the PWM converter.

   A FREQUENCY RESPONSE ORIENTED APPROACH TO ROTOR LOSSES EVALUATION IN CONVERTER OPERATED SYNCHRONOUS MACHINES
By M. P. Bottino; G. B. Denegri; M. Invernizzi; A. Morini [View]
[Download]

Abstract: The distorted waveforms of stator currents in converter fed synchronous machines give rise to additional rotor losses. The knowledge of these losses in advance is important as far as both machine design and performance are concerned. In the paper, an approach to rotor losses evaluation is proposed based on the operational transfer functions of the machine. Results are presented with reference to a variable frequency synchronous motor drive.

   Running Simulation of the Superconductive Magnetically Levitated System
By S. Ohashi; K. Higashi; H. Ohsaki; E. Masada [View]
[Download]

Abstract: The superconductive Maglev system, which is based on the electrodynamic suspension (EDS) and driven by the linear synchronous motor (LSM) can operate up to 500 km/h, keeping the gap length between bogie and guideway about l0 cm. Although the superconductive EDS system has the advantage of stable levitation without active control, various electromagnetic or mechanical disturbances can cause the change of gap length and the displacement or oscillation of the bogie. So it is very important to analyze the characteristics of bogie motion with numerical simulation and verify them with operational results on the test track as well. In this paper oscillatory motion of the running bogie is studied. Damping characteristics of vertical motion are calculated. And dependence of damping characteristics on resistance of the levitation coils and running speed, are shown. From the results, it is found that increasing speed has same effect as reducing resistance of the levitation coils. 3-dimensional running simulation of the superconductive Maglev bogie are shown too. The bogie motion is calculated when the lateral force acts on the bogie to find bogie's behaviour.

   MODELLING AND RECURSIVE IDENTIFICATION OF PARAMETERS OF SATURATED INDUCTION MACHINES
By H. Al Miah; P. Lagonotte; J-C. Trigeassou [View]
[Download]

Abstract: This work presents modelling and on line parameters identification of a saturated induction machine. A recursive algorithm of the Newton type was used in this work. The model studied was non linear compared to parameters, and also multi-input multi-output. For this reason we have adopted a multi-dimensional algorithm for this case.

   METHODOLOGY TO DETERMINE THE FLUX CONTROL SENSITIVITY TO PARAMETER UNCERTAINTIES OF INDUCTION MOTOR F.O.C. STRATEGIES USING FLUX OBSERVERS
By B. Robyns; X. Roboam [View]
[Download]

Abstract: A methodology is proposed to determine analytically, in steady state, flux amplitude and orientation errors, due to parameter uncertainties, in field-oriented control using a flux observer. This method is applied to a reduced order observer. A modification in the classical determination of the slip frequency which reduces the flux orientation error is also proposed.

   EMULATOR OF STATIC CONVERTERS / ELECTRICAL MACHINES APPLICATION TO THE TEST OF NEW CONTROL ALGORITHMS
By S. Ben Saoud; F. Chouzal; B. Dagues; J. C. Hapiot [View]
[Download]

Abstract: Despite the constant improvement of its performances, numerical simulation still remains insufficient to guarantee the correct running of the control unit when connected to the real process. To solve this problem, an intermediate testing step between the simulation and the experimentation has been developed : Emulation. This paper presents a static converters / electrical machines emulator and points out the basic concepts that have led to its design. The problems associated to the temporal communication and the synchronisation between this emulator and the real digital control unit are detailed. This method has been verified by experimentation.

   SENSITIVITY OF THE FLUX CONTROL TO PARAMETER UNCERTAINTIES IN INDUCTION MOTOR DIRECT F.O.C. STRATEGIES USING A SIMPLE FLUX ESTIMATION
By B. Robyns; H. Buyse [View]
[Download]

Abstract: This paper concerns an induction motor direct field oriented control strategy with a simple flux estimation. lt shows how the flux control sensitivity depends on the current control strategy, the way of computing the d-q reference frame speed and the way of computing the decoupling terms. The interesting properties of a novel version of the direct field oriented control scheme are then shown.

   Simulation of Power-Losses and Ripple-Torques of lnverter-fed Three-Phase Motors
By P.-K. Budig [View]
[Download]

Abstract: lnverters supplying three-phase motors with a series of harmonic voltages and currents. These currents cause additional I²R-losses and ripple torques. With the program BEMOVER it is possible to calculate these effects under consideration of the eddy-current effect. Thus it is possible to intensify the dialog between the motor- and inverter specialists to improve the efficiency and the interaction of motor and drive system.

   AN ANALYTICAL STUDY OF HARMONIC VOLTAGES, CURRENTS AND TORQUE RIPPLES IN DRIVES FED WITH OPTIMISED PWM VOLTAGE PATTERNS
By Albert Wiart; Jean Bonal [View]
[Download]

Abstract: Through a purely analytical method some simple and clear formulae are found which define the harmonic voltages and currents and the torque ripple in drive fed with optimised PWM voltage patterns obtained by adding some specific zero sequence waves to the sinusoïdal modulation wave.

EPE 1995 - 45 - Dialogue Session DS6a: Drives: Simulation and User/Application Experiences
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 1995 - Conference > EPE 1995 - 45 - Dialogue Session DS6a: Drives: Simulation and User/Application Experiences
	[return to parent folder]

	ESTIMATION OF INDUCTION MOTOR SPEED IN FUZZY LOGIC SYSTEM By Z. Krzeminski	[View] [Download]
Abstract: The observer system for the induction motor with simultaneous estimation of the rotor speed is analysed. The multiscalar model dependencies for steady state are used to calculate the rotor speed. Errors in dynamical states of the system are caused by inaccuracy of the calculated speed. A fuzzy logic system is proposed to correct the rotor speed. The proposed system is applied to the non-linearly controlled induction motor fed by voltage source inverter and results of simulations are presented.

	POLE PLACEMENT STRATEGY FOR SLIDING MODE CONTROLLER IN Z-RANGE By P. Matthes	[View] [Download]
Abstract: The paper deals with the design of a sliding mode speed controller for an inverter fed induction machine. Efficient system pole locations are used. A self developed program supports the menue-assisted controller optimisation.

	DYNAMIC ANALYSIS OF NON-SINUSOIDALLY SUPPLIED INDUCTION MACHINE BASED ON THE FINITE ELEMENT METHOD By R. De Weerdt; K. Hameyer; R. Belmans	[View] [Download]
Abstract: The analysis of a squirrel-cage induction motor based on the finite element calculation is described. The finite element calculations are used to generate an extended motor model describing the motor as a set of coupled windings. The significant difference with conventional motor models as the d-q-model is that the inductance matrix in the model includes saturation and motor slotting in a natural way. Both are described as a ripple on the inductances. Once the model is calculated, it is used in simulations by solving the set of voltage differential equations describing the coupled windings. Simulations are performed, both with and without motion. Voltage supply can be both sinusoïdal and time dependent when an inverter is used.

	MODELLING AND SIMULATION OF ELECTRICAL DRIVES AT NORMAL AND FAULT CONDITIONS By R. Szczesny; P.J. Chrzan; K. Iwan	[View] [Download]
Abstract: An approach to modelling and simulation of electrical drives at normal and fault conditions is described. Modern simulation methods and models of converter-machine associations are presented. The application of different software packages in converter systems simulation are discussed and TCAD package is chosen. The principal features of TCAD version for Windows are presented and its usefulness for normal and fault conditions study is proved. For an example of application the induction motor fed by voltage source PWM inverter is chosen. Simulation and experimental results for both normal and fault conditions are given and a good agreement has been reached. In the conclusions some suggestions concerning simulation methodology in research and engineering practice are given.

	FUZZY LOGIC SUPERVISION OF ADAPTIVE GENERALIZED PREDICTIVE CONTROL OF INDUCTION MOTOR By M. A. Brdys; W. L. Sim	[View] [Download]
Abstract: The recently proposed Adaptive Generalized Predictive Control (GPC) for induction motor in [3] is further investigated. A supervisory controller is proposed which updates on-line GPC control loop weights to improve the transients responses and robustness. The design of the supervisory controller employs a fuzzy logic philosophy. The approach is motivated by the fact that relationship between weights and the transient properties cannot be realized by a suitable mathematical model while sufficient qualitative knowledge exists. Feasibility of such an approach is demonstrated by simulation studies of the overall controller operation.

	MODELLING AND OPERATION OF A NONLINEAR SWITCHED RELUCTANCE MOTOR DRIVE BASED ON FUZZY LOGIC By C. Elmas; O. F. Bay	[View] [Download]
Abstract: In recent years, switched reluctance motors have occupied a wide spectrum of applications for variable speed drives, because of their simplicity and versatility of control. This paper introduces an attempt to use fuzzy logic to model and control a switched reluctance motor drive. Fuzzy based modelling does not require an accurate mathematical model which is very difficult to obtain from a switched reluctance motor (SRM) because of its inherit nonlinearities. An application of fuzzy sets to the SRM drive control was also applied to the speed loop, replacing the conventional PI controller. The results of applying the fuzzy logic controller (FLC) to SRM were compared to those obtained by the application of a conventional PI system. Compared to a PI control the fuzzy logic control provided a better response in terms of accuracy, and insensitivity to changes in operating conditions. The fuzzy controller shows robustness over a wide range of operations.

	CONTROL OF SELF-COMMUTATED SYNCHRONOUS MOTOR WITH DYNAMIC DECOUPLING By K. Zawirski	[View] [Download]
Abstract: In the paper a theoretical background of a new control method for self-commutated synchronous motor, which improves drives dynamic properties is proposed. The method bases on analysis of existing cross-couplings in control structure and compensation their influence by introduction of control decoupling blocks generating proper signals. This approach becomes similar to the method used for vector-oriented control in the case of drive with autonomous inverter.

	REDUCED ORDER MODEL OF AN INDUCTION MOTOR DRIVE: SENSITIVITY STUDY FOR AN ADAPTIVE CONTROL By I. Slama-Belkhodja; B. de Fornel	[View] [Download]
Abstract: The induction motor, supplied by a chopper-filter-inverter system is modelled by a nonlinear seven order system. Two reduced order models are presented: An Input/Output one identified with the Recursive Least Squares algorithm and an analitic one. Their sensivities to parameter variations are discussed in vue to apply an adaptive control.

	A SIMULATION TOOL FOR INDUCTION MOTOR CONTROL By P. Marino; V. Mungiguerra; M. Porzio; R. Setola; F. Vasca	[View] [Download]
Abstract: A simulation tool for the dynamic analysis of scalar and vector controlled induction motor is proposed. The tool is builded under the MATLAB with SIMULINK programme environment. The ac drive considered consists of choppered power supply, filters, voltage source inverter, induction motor, mechanical load, controller. Each element of the whole system is represented as a Simulink block and it can be independently simulated or connected to the others in order to analyze their interaction. The tool is used to design and to test the effectiveness of an extended Kalman filter as :flux observer and rotor resistance estimator. Two different solutions to ensure good filter performance in the presence of a low switching frequency inverter are proposed: the variable sampling period technique and the voltage averaging approach. Simulation results on an high power ac drive are also provided.

	CONTROL OF INDUCTION MOTOR DRIVES USING DISCRETE PREDICTIVE FRAME By B. Jacquot; B. Delemontey; B. de Fornel; C. Iung; J. Bavard	[View] [Download]
Abstract: This paper presents a high dynamic control of high-power induction motor fed from PWM inverter. First, the field-oriented control is presented. This method uses continuous motor modelling. Operating at low switching frequency, sampling leads to non-negligible approximations during high transient. So a new discrete model that takes into account PWM is developped. Its utilization allows exceptional torque dynamical, a great accuracy, and a good decoupling between torque and flux.

	ADVANCES IN SWITCHED RELUCTANCE DRIVE SYSTEM DYNAMIC SIMULATION By C. R. Elliott; J. M. Stephenson; M. C. McClelland	[View] [Download]
Abstract: This paper describes the simulation of complete Switched Reluctance drive systems with a commercially available dynamic simulation package (Simulink™). A well established technique for modelling the non-linear characteristics of the Switched Reluctance Motor (SRM) is used, and the reasons for this justified. Experimental validation of the simulator is provided along with example simulation results. The resulting system is user friendly and allows rapid model building but with simulation time within practical limits.

	PARAMETER ESTIMATION FOR INDUCTION MACHINES By R. J. A. Gorter; J. L. Duarte; P. P. J. van den Bosch	[View] [Download]
Abstract: An identification procedure for estimation of induction machine parameters based on on-line measured data is proposed. By utilizing the switching harmonics of the inverter all machine parameters, except the stator resistance, can be identified in an operating point. An important step in the identification procedure is the transformation of measured signals to rotor coordinates. This yields the possibility to estimate both single-cage as double-cage rotor models. The method is tested on a double-cage 11 kW induction machine.

	ELECTRIC ENERGY CONSERVATION IN PUMPING PROCESSES AT A REFINERY By R. M. Stephan; M. Americo; A. G. G. Lima; A. Rodrigues	[View] [Download]
Abstract: This paper describes a joint project carried out by UFRJ, CEPEL and REDUC partially sponsored by PROCEL (Brazilian Program on Electric Energy Conservation). The main objective was to study the application of Adjustable Speed Drives (ASD) systems to control the flow of oil in substitution to throttling valves. Energy saving, payback time and power harmonic aspects are considered.

	SIMULATION OF A PWM CONVERTER USING ICAP/4 TO VERIFY THE DESIGN By M. Deghadi; J. D. Triplett	[View] [Download]
Abstract: A three phase Pulse-Width Modulated (PWM) converter is ready for building. The circuit will first be simulated using ICAP/4 software to verify the design. This paper will describe the design and show the simulation results for the PWM converter.

	A FREQUENCY RESPONSE ORIENTED APPROACH TO ROTOR LOSSES EVALUATION IN CONVERTER OPERATED SYNCHRONOUS MACHINES By M. P. Bottino; G. B. Denegri; M. Invernizzi; A. Morini	[View] [Download]
Abstract: The distorted waveforms of stator currents in converter fed synchronous machines give rise to additional rotor losses. The knowledge of these losses in advance is important as far as both machine design and performance are concerned. In the paper, an approach to rotor losses evaluation is proposed based on the operational transfer functions of the machine. Results are presented with reference to a variable frequency synchronous motor drive.

	Running Simulation of the Superconductive Magnetically Levitated System By S. Ohashi; K. Higashi; H. Ohsaki; E. Masada	[View] [Download]
Abstract: The superconductive Maglev system, which is based on the electrodynamic suspension (EDS) and driven by the linear synchronous motor (LSM) can operate up to 500 km/h, keeping the gap length between bogie and guideway about l0 cm. Although the superconductive EDS system has the advantage of stable levitation without active control, various electromagnetic or mechanical disturbances can cause the change of gap length and the displacement or oscillation of the bogie. So it is very important to analyze the characteristics of bogie motion with numerical simulation and verify them with operational results on the test track as well. In this paper oscillatory motion of the running bogie is studied. Damping characteristics of vertical motion are calculated. And dependence of damping characteristics on resistance of the levitation coils and running speed, are shown. From the results, it is found that increasing speed has same effect as reducing resistance of the levitation coils. 3-dimensional running simulation of the superconductive Maglev bogie are shown too. The bogie motion is calculated when the lateral force acts on the bogie to find bogie's behaviour.

	MODELLING AND RECURSIVE IDENTIFICATION OF PARAMETERS OF SATURATED INDUCTION MACHINES By H. Al Miah; P. Lagonotte; J-C. Trigeassou	[View] [Download]
Abstract: This work presents modelling and on line parameters identification of a saturated induction machine. A recursive algorithm of the Newton type was used in this work. The model studied was non linear compared to parameters, and also multi-input multi-output. For this reason we have adopted a multi-dimensional algorithm for this case.

	METHODOLOGY TO DETERMINE THE FLUX CONTROL SENSITIVITY TO PARAMETER UNCERTAINTIES OF INDUCTION MOTOR F.O.C. STRATEGIES USING FLUX OBSERVERS By B. Robyns; X. Roboam	[View] [Download]
Abstract: A methodology is proposed to determine analytically, in steady state, flux amplitude and orientation errors, due to parameter uncertainties, in field-oriented control using a flux observer. This method is applied to a reduced order observer. A modification in the classical determination of the slip frequency which reduces the flux orientation error is also proposed.

	EMULATOR OF STATIC CONVERTERS / ELECTRICAL MACHINES APPLICATION TO THE TEST OF NEW CONTROL ALGORITHMS By S. Ben Saoud; F. Chouzal; B. Dagues; J. C. Hapiot	[View] [Download]
Abstract: Despite the constant improvement of its performances, numerical simulation still remains insufficient to guarantee the correct running of the control unit when connected to the real process. To solve this problem, an intermediate testing step between the simulation and the experimentation has been developed : Emulation. This paper presents a static converters / electrical machines emulator and points out the basic concepts that have led to its design. The problems associated to the temporal communication and the synchronisation between this emulator and the real digital control unit are detailed. This method has been verified by experimentation.

	SENSITIVITY OF THE FLUX CONTROL TO PARAMETER UNCERTAINTIES IN INDUCTION MOTOR DIRECT F.O.C. STRATEGIES USING A SIMPLE FLUX ESTIMATION By B. Robyns; H. Buyse	[View] [Download]
Abstract: This paper concerns an induction motor direct field oriented control strategy with a simple flux estimation. lt shows how the flux control sensitivity depends on the current control strategy, the way of computing the d-q reference frame speed and the way of computing the decoupling terms. The interesting properties of a novel version of the direct field oriented control scheme are then shown.

	Simulation of Power-Losses and Ripple-Torques of lnverter-fed Three-Phase Motors By P.-K. Budig	[View] [Download]
Abstract: lnverters supplying three-phase motors with a series of harmonic voltages and currents. These currents cause additional I²R-losses and ripple torques. With the program BEMOVER it is possible to calculate these effects under consideration of the eddy-current effect. Thus it is possible to intensify the dialog between the motor- and inverter specialists to improve the efficiency and the interaction of motor and drive system.

	AN ANALYTICAL STUDY OF HARMONIC VOLTAGES, CURRENTS AND TORQUE RIPPLES IN DRIVES FED WITH OPTIMISED PWM VOLTAGE PATTERNS By Albert Wiart; Jean Bonal	[View] [Download]
Abstract: Through a purely analytical method some simple and clear formulae are found which define the harmonic voltages and currents and the torque ripple in drive fed with optimised PWM voltage patterns obtained by adding some specific zero sequence waves to the sinusoïdal modulation wave.